Field Projects are a part of every phase of research at RCP. Through its field projects, which are often focused on solving a real-world business problem, RCP has studied the effectiveness of hydraulic fracturing in the Denver-Julesburg (DJ), Eagle Ford and Permian basins in the US, Vaca Muerta in Argentina, and Raudhatain in the Middle East. This research provides valuable insights to industry and lessons learned from this work include: optimal well spacing, lateral and vertical dimensions of created fractures, understanding best zones to fracture from seismic inversion parameters, and the value of time-lapse seismic when gas comes out of solution to map depleted zones. Our current field projects include:
chalk bluff, colorado
The Chalk Bluff DJ Basin Project is RCP’s primary field project for Phase 18 research. The project focuses on the integration of a comprehensive data set provided by HighPoint Resources. What is particularly unique and exciting about this project is that the ongoing data collection and acquisition presents RCP with the opportunity to influence subsequent development and production of this reservoir. The ultimate goals of the project are to increase recovery and optimize hydraulic fracturing operations for cost-effective development of this unconventional reservoir.
Within the main goals of the project, there are several sub-objectives driven by the quantity and variety of data available. The datasets made available to RCP includes high quality surface seismic and microseismic, well log, fiber optics (including VSP, borehole microseismic, DTS and DAS), tiltmeter, geochemistry, completions and production data. The sub-objectives that can be addressed through these data are:
- Understanding drivers and processes of vertical and horizontal connectivity
- Understanding parent-child well interferences and how to mitigate them
- Evaluating and optimizing completion designs that maximize DSU economics
- Examining how fractures respond to existing faults and subsurface structural heterogeneity
- Developing new reservoir analysis methods (fiber optics, geochemistry, etc.)
- Identifying and interpreting correlations among production, completion efficiency, hydraulic fracture properties, and subsurface structures through machine learning-based multi-variable analysis
- Understanding the value of EOR for field implementation in a future phase of the project
The variety of data enables RCP to address multiple challenging questions, and provides the opportunity for a multidisciplinary team of petroleum engineering, geology, and geophysics students to collaborate on the project. Through the 22 horizontal well program and supplemental datasets from HighPoint Resources, RCP students will characterize the ongoing production and influence subsequent development of this unconventional reservoir, while advancing the knowledge and techniques that will aid in the characterization of other basins across the globe.
A diagram showing the 22 wells drilled by High Point Resources (running N-S) and their relative positions. Wells with permanent fiber installed outside their casings are shown in red. The diagonal NW-SE wells shown in blue are pre-existing legacy producing wells. A single vertical pilot well, indicated by the green circle, is also part of the data acquisition program. The grey polygons outlined in yellow represent faults, indicating where injection losses have been observed.
Midland Basin, Texas
The Midland Basin Project centers on the use of Distributed Acoustic Sensing (DAS) to conduct Vertical Seismic Profiling (VSP) surveys after each stage of hydraulic fracturing. It is a continuation of the previous Phase XVII Wolfcamp Project, and for the current Phase XVIII, Apache has provided an improved dataset acquired with engineered fiber-optic cable technology in the Midland Basin. The goal of the project is to characterize the stage-by-stage geometry and evolution of the stimulated rock volume (SRV) through analyzing time shifts and scattered waves observed after each survey.
The project objectives include:
- Use of scattered waves and time-shifts to estimate stage-by-stage the height, elastic rock properties, and leak-off behavior of the stimulated rock volume
- Understand the interference of wells in a zipper group on the time-lapse seismic response and understanding of horizontal and vertical connectivity between wells
- Design of optimal acquisition geometries to enhance characterizing properties of the SRV
Top: Well and fracture plane geometries for VSP shot 25, taken after completion of stage 16 of well 9Bf, stage 12 of well 10D, and stage 30 of well 11A. Bottom: VSP shot 25 from toe source time-lapse response (baseline is subtracted). Incident P-wave and PS-wave scattered on SRV is highlighted with arrows. Modified from Titov et. al., SEG 2020.
NORTH SEA 4D
RCP initiated a new research project in the spring of 2019 with a dataset provided by Lundin Norway. The Edvard Grieg oil field was discovered in 2007 in the Norwegian North Sea and is operated by Lundin Norway. The reservoir lies in a half graben in Haugaland High, composed of multi-source sediment accumulation bounded by unconformities. The late Triassic to early Cretaceous reservoir is composed of aeolian sands, alluvial sands, conglomerate, and shallow marine sands. Imaging challenges arise from the depositional complexity of the field and detailed analysis must be done to plan for future development. RCP recently performed joint PP-PS prestack inversion of the Baseline (2016) and Monitor 1 (2018) OBC surveys to separate saturation and pressure changes (Daneshvar, 2020). The project continues with incorporation of the second monitor survey acquired during the summer of 2020. This provides the opportunity to further monitor 4-D pressure and saturation changes, as well as compare time-lapse processing products from two seismic processing vendors.
MIDDLE EAST PROJECT, Kuwait
Imaging the deep Jurassic shale and carbonate reservoirs below salt and anhydrite layers is a well-known imaging challenge addressed in this research. This fractured reservoir characterization study is a collaboration with Kuwait Oil Company (KOC) to enhance sub-surface understanding for improved reservoir development and management of deep Jurassic age fractured carbonate play. Available data includes well logs, VSP and seismic data. Initial work concentrated on improving the characterization of the resource play of the Najmah formation.
The primary focus of this research phase is reservoir characterization of the Marrat formation. Research will incorporate advanced synthetic modeling and field data application. The goals include the development of an optimized workflow to attenuate multiples, and a calibrated and quantitative anisotropic mapping technique for reservoir development and sweet spot identification.
Project results will aid in the development of new technologies for similar resource areas throughout the Middle East.
Left) An ideal synthetic model with primary waves only. The primary amplitudes are obvious in mid and far offsets. Middle) A synthetic model with primary and interbed multiple waves. The primary amplitudes in mid and far offsets are interfered with multiples. Right) A super gather at a well location colored by incident angles. The seismic amplitude of mid and far offsets are possibly contaminated by multiples and converted waves. The field seismogram is very similar to the primary with multiple model. The maximum incidence angle that can be used for any further analysis is less than 25 degrees at the reservoir interval.
Deepwater project, Brazil
The deepwater offshore Brazil project is a conventional post-salt turbiditic sandstone reservoir with excellent perm-porosity conditions, with more than 75% NTG and saturated by heavy oil.
Petrobras provides the data for this project. The pilot Permanent Monitoring System (PRM) has very high repeatability, composed of three seismic surveys, shot approximately one year apart. The high repeatability enabled feasibility of the monitoring, once modeling indicated there would be very low seismic amplitude changes due to fluid substitution (production and injection). The seismic data is very high quality, acquired with 4-component fiber optics sensors and full azimuth coverage. The project integrates logs from more than 50 wells, lab ultrasonic measured elastic properties, petrophysical information, interpreted horizons and production information.
The main project objective is characterization and monitoring of the reservoir, using a multidisciplinary approach integrating geology, geophysics and petroleum engineering. The research will utilize advanced technologies for data investigations. Lessons learned in this project may be applied to other future fields.
Top) NE-SW lines from 4D time-shifts (left) and difference amplitudes (right). Bottom) Map view of the mean 4D time-shifts inside the reservoir interval. The position of the line shown in the top is represented in the map as a dashed black line. The red arrows over the lines and the map highlight an injection effect (speed-up), while the yellow arrows highlight a zone showing a production effect (slow-down).